Method of manufacturing gas-tight material



' Patented Apr. 16, 1929.

UNITED STATES PATENT OFFICE.

HANS STBOIBL, OF BERLIN-TEMJPELHOF, GERMANY, ASSIGNOR, BY MESNE ASSIGN- Ems, TO LUFTSGEIFIBAU ZEPPELIN G. M. B. 11., OF FRIEDRICHSHAFEN, BO-

DIDI'SEE, GERMANY.

METHOD OF MANUFACTURING GAS-TIIIGHT MATERIAL.

Ito Drawing. Application filed February 17,1926,

My invention relates to gas-tight material, es ecially for balloons, cells of airships an the like, which is manufactured from goldbeaters skin, other animal skins or .10 means of an agglutinant soluble in water,

like gelatine, isinglass', casein or the like, to which agglutinant an admixture of a substance adapted for rendering the glue elastic is given, as for example gycerin, Turkey red oil or the like. This admixture of softening substances reduces the agglutinative qualities of the adhesive substances, especially of gelatine. Therefore it causes an increase in consumption of these substances and thereby an increase of weight also.

According to my invention I am doing away with these-drawbacks by applying the softening substances after the combination I of skins and fabric is performed. This application may. be made from the skin side of the combined material or from the fabric side, or from both sides. It may be advisable to make a weak admixture of softening substance to the agglutinant but the essen- 0 tial portion should be a plied after the combination of skin wit fabric. By this method a big saving in softening material is attained thereby also saving in weight, which is of great importance especially with airships. The flexibility of the finished material is thesame as if a larger amount of softening substances were mixed to the agglutiserial No. 88,968, and in Germany March 17, 1925.

nant, I dare say it is even better. I prefer to m x the softening substance with water before its application to the material.

If the saving in weight attained by-following my new method of manufacture were only 3 grams per square meter, for example, yet the advantage would be considerable, because with thebig airships now under construction, in which 60,000 square meters of balloon material and more arerequired, the gain in useful lift would amount to 180 kilos and more, which equals the weight of two to three additional passengers.

I do not want to limit myself to the exact details of this specification as substitutes and equivalents for the substances mentioned will occur to those skilled in the art.

What I claim is:

1. The process of making a gas-tight material which consists in appl ing a substance having the characteristics 0 glue to an animal skin, in uniting said skin with a layer of fabric and in then applying a substance adapted to render said first substance elastic.

2. The method of manufacturing a gast-ight material which consists in first uniting an animal skin to a fabric by means of an agglutinant and in thereafter applying to the combined material a substance adapted to render said agglutinant elastic.

3. The method of manufacturing a balloon envelope material which consists in uniting goldbeaters skins to a fabric by means of gelatine and in thereafter applying glycerin to the combined material.

HANS STROBL. 

